I thought you were onyl meant to drink your own urine as it has what your body needs.
As your friends urine should be for her, thats what i thought ?
Also the better your diet the better the urine will be for you, so coffee would make the urine less healthy as it dehydrates the body which effects the bladder
This is what i do, drink my first morning mid stream urine. I've flet very good from this !!